Add gyp machinery to build with packed ARM relative relocations.

build/java_apk.gypi

Index: build/java_apk.gypi
diff --git a/build/java_apk.gypi b/build/java_apk.gypi
index 5f3653dd2f7594e769cadac5d97236e150208253..fb0cf8df4775b4eb6e1bc572eb5494c10100331f 100644
--- a/build/java_apk.gypi
+++ b/build/java_apk.gypi
@@ -46,6 +46,8 @@
 #    By default, the package given in AndroidManifest.xml will be used.
 #  use_chromium_linker - Enable the content dynamic linker that allows sharing the
 #    RELRO section of the native libraries between the different processes.
+#  use_relocation_packer - Enable relocation packing. Relies on the chromium
+#    linker, so use_chromium_linker must also be enabled.
 #  enable_chromium_linker_tests - Enable the content dynamic linker test support
 #    code. This allows a test APK to inject a Linker.TestRunner instance at
 #    runtime. Should only be used by the chromium_linker_test_apk target!!
@@ -93,6 +95,7 @@
     'instr_stamp': '<(intermediate_dir)/instr.stamp',
     'jar_stamp': '<(intermediate_dir)/jar.stamp',
     'obfuscate_stamp': '<(intermediate_dir)/obfuscate.stamp',
+    'pack_stamp': '<(intermediate_dir)/pack.stamp',

[rmcilroy, 2014/06/27 11:14:54]

nit - pack_relocations.stamp

[simonb (inactive), 2014/06/30 16:23:23]

Done.

     'strip_stamp': '<(intermediate_dir)/strip.stamp',
     'classes_dir': '<(intermediate_dir)/classes/2',
     'javac_includes': [],
@@ -124,6 +127,7 @@
         'native_lib_target%': '',
         'native_lib_version_name%': '',
         'use_chromium_linker%' : 0,
+        'use_relocation_packer%' : 0,
         'enable_chromium_linker_tests%': 0,
         'is_test_apk%': 0,
       },
@@ -148,6 +152,7 @@
     'native_lib_target%': '',
     'native_lib_version_name%': '',
     'use_chromium_linker%' : 0,
+    'use_relocation_packer%' : 0,
     'enable_chromium_linker_tests%': 0,
     'emma_instrument%': '<(emma_instrument)',
     'apk_package_native_libs_dir': '<(apk_package_native_libs_dir)',
@@ -316,7 +321,7 @@
           'action_name': 'strip_native_libraries',
           'variables': {
             'ordered_libraries_file%': '<(ordered_libraries_file)',
-            'stripped_libraries_dir': '<(libraries_source_dir)',
+            'stripped_libraries_dir': '<(SHARED_INTERMEDIATE_DIR)',

[rmcilroy, 2014/06/27 11:14:55]

I'm not entirely familiar with the output directory structure, but I think we
should be  using a new directory here rather than re-using
SHARED_INTERMEDIATE_DIR (which presumably holds the unstriped version
currently).

[simonb (inactive), 2014/06/30 16:23:23]

SHARED_INTERMEDIATE_DIR doesn't currently hold unstripped libs.  These are in
SHARED_LIB_DIR.  Previous to this change the strip action stripped and copied
from SHARED_LIB_DIR into the apk staging dir.  Now the strip and copy outputs to
an intermediate dir, and relocation packing does the final copy out to apk
staging.  SHARED_INTERMEDIATE_DIR is the directory gyp supplies for
communicating between actions.

I've amended the code to create a new subdirectory under
SHARED_INTERMEDIATE_DIR, just for communicating between strip_native_libraries
and pack_arm_relocations.  Hopefully this makes what is happening clearer.

[rmcilroy, 2014/07/01 11:13:02]

This is perfect, thanks for making the change.

             'input_paths': [
               '<@(native_libs_paths)',
               '<@(extra_native_libs)',
@@ -325,6 +330,29 @@
           },
           'includes': ['../build/android/strip_native_libraries.gypi'],
         },
+        {
+          'action_name': 'pack_arm_relocations',
+          'variables': {
+            'ordered_libraries_file%': '<(ordered_libraries_file)',
+            'stripped_libraries_dir': '<(SHARED_INTERMEDIATE_DIR)',
+            'packed_libraries_dir': '<(libraries_source_dir)',
+            'input_paths': [
+              '<(strip_stamp)',
+            ],
+            'stamp': '<(pack_stamp)',
+            'conditions': [
+              ['use_chromium_linker == 1 and use_relocation_packer == 1', {

[rmcilroy, 2014/06/27 11:14:55]

Can you make it an error to have "use_relocation_packer == 1" and
"use_chromium_linker == 0" instead of just disabling packing?

[simonb (inactive), 2014/06/30 16:23:23]

Gyp appears to lack any mechanism to raise an exception or otherwise 'error
out'.

[rmcilroy, 2014/07/01 11:13:02]

I was afraid of that.. Thanks for checking.

+                'enable_packing': 1,
+              }, {
+                'enable_packing': 0,
+              }],
+            ],
+          },
+          'dependencies': [
+            'strip_native_libraries',
+          ],
+          'includes': ['../build/android/pack_arm_relocations.gypi'],
+        },
       ],
       'conditions': [
         ['gyp_managed_install == 1', {